Meta-languages describe the structure of information to enable this information to be searched more easily by software systems. XML (eXtensible Markup Language) has emerged as the most important of these Meta-languages and is the base for many languages. XML standards are important for the Semantic Web, many computer based reasoning systems, and for communication between different software applications. Alternative representations of information should not be used in any system being developed now unless the author has examined XML based standards and found them insufficient. Such a situation is highly unlikely. Any software system that does not use these standards will have difficulty communicating with other software systems. Use of a generic standard keeps open the possibility of communication with the widest possible range of other software systems. Use of a domain specific standard targets the communication to a particular domain.

Extensible Markup Language XML is an important standard in the development of ontologies. This language allows for the construction of text documents in which the relationship between concepts is represented. Because it is an accepted standard it is possible to use XML on any type of computer. Further developments such as Resource Description Framework RDF add a layer of standardisation of semantics, above the standardised syntax of XML. It is also possible to represent diagrammatic, and graphical information using a variety of XML called Scalable Vector Graphics (SVG).

These open standard languages can be used for developing the program code of models. It is proposed that software and information represented by the software, be separated but represented in the same open standard searchable way. Software and the information it manipulates are just information that has different uses, there is no reason why software must be represented differently represented differently from other information. So XML can be used both as the information input and output by the application, and for the definition of the model itself. The model can read or write information it represents, and the information can read from or write to the model. This recursion makes 'meta-programming' possible. Meta programming is writing of programs by other programs. The purpose of this is to provide a cascading series of layers that translate a relatively easy to use visual representation of a problem to be modelled, into code that can be run by present day compilers and interpreters. This is to make it easier for computer literate non-programmers to specify instructions to a computer, without learning and writing code in computer languages. To achieve this, any layer of software or information must be able to read the code or the information represented in any other. Code and information are only separated out as a matter of design choice to aid human comprehension, they can be represented in the same way using the same kinds of open standard languages.

Meta Language Links

3 Dmitriev, S. (2004). Language Oriented Programming: The Next Programming Paradigm, http://www.onboard.jetbrains.com/is1/articles/04/10/lop/.

4 Mens, K., Michiels, I., Wuyts, R. (2002). Supporting Software Development through Declaratively Codified Programming Patterns, Expert Systems with Applications, 23: 405-413.